Baynes' Celtics thrash Cavs in NBA opener

The Celtics have stifled the Cavaliers to win game one of their NBA Eastern Conference finals series

Aron Baynes and his Boston Celtics have handed the Cleveland Cavaliers a 25-point shellacking to claim game one of the NBA Eastern Conference Finals.

The Cavs' perennial All-Star LeBron James entered the series averaging 34 points per game, but he had no answer for the Celtics' stifling defence and free-flowing, unselfish offence.

The Celtics won 108-83 in Boston on Sunday and were always in control of the game.

It sends an ominous warning to the James-led Cavs who are looking for their fourth successive Eastern Conference title and berth in the championship series.

Boston opened up an early 21-7 lead and finished the first quarter up 36-18, extended it to 61-35 at halftime and at the start of the third quarter were up 78-64.

James missed 11 of his 16 field goal attempts for 15 points, seven rebounds, nine assists and seven turnovers.

Cavs coach Tyronn Lue put up the white flag with seven minutes to go, subbing James out and leaving him on the bench for the rest of the game.

Queenslander Baynes started every game in the Celtics' semi-final series victory over Ben Simmons' Philadelphia 76ers when he battled centre Joel Embiid, but was relegated to the bench for the start of game one against the Cavs.

He still had a major impact on the game in his 25 minutes on the court, using his 208cm tall, 120kg body to add steel to the Celtics' defence, deflect passes, alter Cavs shots, set screens and help stifle James.

Baynes had four points, eight rebounds, two steals and one block for the game.

Celtics coach Brad Stevens went with forward Marcus Morris in the starting line-up to create a smaller, mobile line-up to combat the Cavs who started three-point shooting forward Kevin Love alongside James and guards Kyle Korver, George Hill and JR Smith.

Korver and Hill had just five points each and Smith was also ineffective with four.

Stevens heaped praise on the "selfless" Baynes for his team-first attitude in accepting the decision.

"Being able to take him in and out of the lineup, he's set a great example for everybody else," Stevens, discussing Baynes' team-first attitude, said.

Morris had controversially boasted before the series opener about his ability to defend James.

Morris picked up three early fouls, forcing Stevens to call on Baynes throughout the game.